She says landholders have been told to stop their livestock from drinking from the waterways.

The minister says some relief may be on the way with approval now given for a plan to put in temporary weirs on the waterways to help raise the water level.

Federal Environment Minister Peter Garrett has decided the plan for weirs, or regulators, in the lower reaches of the drought-stricken Murray does not need further environmental assessment.

SA Opposition Leader Martin Hamilton-Smith says he is concerned about the approval process for temporary weirs.

"Very surprised that they've decided to barge ahead with another engineering solution without an environmental impact statement," he said.

The SA Government says almost 400 tonnes of limestone has been put in the affected area to help neutralise acid.

Residents opposed

Di Bell, of the Lower Lakes and Coorong Action Group, says the decision for weirs has been made too quickly and deserved a proper environmental study.

She says the group's own testing results show healthy pH levels.

"We have been to the sites, the most recent sites, we were there on Friday and on Saturday and we have been at the exact sites where they have been getting their low readings," she said.

"One, I think, was 2.68 that they got on May 3, we have not been able to duplicate that.

"We do not think the threat is as dire. What we are asking for is for them to show us their material and for us to be able to work through the model they have used because we have been doing independent readings and observations and we cannot duplicate the rather scary readings they are getting."

"A dramatic and drastic measure such as this being proposed by the State Government at a time when the environment in the area is so fragile, we need to ensure we have the best scientific and environmental assessments possible," she said.

Goolwa tourism operator Jock Veenstra says the weirs will not only be good for waterfront property owners, but boat users.

"Prior to low water levels we had 1,000 boats moored in all the marinas in Goolwa, so we went back to, you know, between 300 and 400 boats," he said.

"Hopefully with higher water levels we can start attracting some boats back to Goolwa again."